Forking and cloning MEPP2 from GitHub

In order to become a MEPP2 contributor, you should be at ease with the following usages of git (version control system)):

git for beginners (that refers to a git install how-to and also provides an interactive tutorial)
Collaborating with git (that mainly introduces the git remote, git fetch, git push and git pull commands)
Working within a forking workflow, that is the recommended workflow for MEPP2 (as opposed to using e.g. a centralized workflow)

Then you can proceed with

Creating your own github account (if not already done). In doing so, please do choose a login that is unambiguous and straightforward to identify you: this will ease the burden of IP tracking. For example use something like FirstnameLastname or FirstnameLastnameOrganisationname where the "Organisation Name" is the one you will be using while contributing code to MEPP2. For the rest of this inception description we shall assume that you signed in as YourLogin.
Once signed in, you should fork the MEPP2 repository (Github web interface provides a single button method for this: look in the upper right section of the MEPP2 repository home page)
On your desktop machine, you can now (git) clone your fork. When doing so on a CLI you could use something similar to the following command:
git clone https://github.com/YourLogin/MEPP2

Contributing to MEPP2 on GitHub

To submit your own code for integration into the MEPP2 main repository, proceed as usually in a GitHub forking workflow:

commit your code to your local clone of MEPP2
push your local commits to your fork of MEPP2 on GitHub
open a Pull Request from your fork of MEPP2 on GitHub
check the continuous integration results: if one build fail, fix the issue then try again until all builds pass without error
when the continuous integration succeeds, a MEPP2 maintainer will integrate your code into the main repository.